Trident Volume Group Snapshots

[jwebster7]

Trident 25.06 adds support for Kubernetes Volume Group Snapshots (tested with v1beta1) with ONTAP-SAN volumes. This feature enables point-in-time, crash-consistent snapshots of multiple Persistent Volumes (PVs) by leveraging NetApp ONTAP’s Consistency Group (CG) capabilities.

Why Volume Group Snapshots?

Trident has long supported Kubernetes Volume Snapshots, allowing admins to snapshot individual Kubernetes PVs with ONTAP storage. However, this doesn't work for scenarios where point-in-time consistency is required between multiple snapshots. With standard Kubernetes Volume Snapshots, neither Kubernetes nor Trident can guarantee point-in-time consistency. 

Kubernetes Volume Group Snapshots

That’s where Kubernetes Volume Group Snapshots come in. This feature allows you to take point-in-time consistent snapshots of a group of PVs.

To support this, Kubernetes introduces three new Custom Resources (CRs):

• VolumeGroupSnapshot 
• VolumeGroupSnapshotContent 
• VolumeGroupSnapshotClass 

At the time of writing, Kubernetes 1.33 will support v1beta1 volume group snapshot CRDs. Trident will automatically detect if these CRDs are present to enable the relevant feature gates in our CSI sidecars. You will also need to enable the group snapshot feature gate in the "external-snapshotter" in Kubernetes. 

 

ONTAP Consistency Groups

Trident leverages ONTAP's Consistency Group (CG) feature to achieve point-in-time consistency for multiple PVs. Trident creates an ONTAP CG to take a group snapshot of a set of volumes. Once the group snapshot is complete, Trident removes the ONTAP CG. This innovation treats CGs in an ephemeral manner.

Creating a Volume Group Snapshot 

Label the PVC(s)

First, administrators will need to group volumes. This can be accomplished by applying a Kubernetes label consisting of their own custom key-value pair. A single Persistent Volume (PV) may be part of multiple groups, and those groups may be entirely disjoint or partially overlapping. For this example, we'll only map the PVC to a single group through the label: "group: myGroup". Labels may also be applied to existing PVCs that are already bound to a PV.

Example

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: pvc1
  labels:
    group: myGroup
spec:
  resources:
    requests:
      storage: 500Mi
  storageClassName: sc1

Create the Volume Group Snapshot Custom Resources

Volume Group Snapshot Class

Then, define a VolumeGroupSnapshotClass CR that specifies all fields necessary. Similar to the Kubernetes VolumeSnapshotClass, a VolumeGroupSnapshotClass CR may be reused for multiple volume group snapshot instances. This connects the group snapshot to the right CSI driver (like Trident). The "driver" field must reference Trident, or the group snapshot will not be created. Depending on your use cases, it may be wise to specify the proper deletion policy. 

You do not have to create a unique VolumeGroupSnapshotClass CR for every group snapshot.

Example

apiVersion: groupsnapshot.storage.k8s.io/v1beta1
kind: VolumeGroupSnapshotClass
metadata:
  name: vgsclass1
driver: csi.trident.netapp.io 
deletionPolicy: Delete 

Volume Group Snapshot

Next, create a VolumeGroupSnapshot CR.

Be sure to specify the aforementioned VolumeGroupSnapshotClass CR and appropriate label. 

Example

apiVersion: groupsnapshot.storage.k8s.io/v1beta1
kind: VolumeGroupSnapshot
metadata:
  name: vgs1
  namespace: trident
spec:
  volumeGroupSnapshotClassName: vgsclass1
  source:
    selector:
      matchLabels:
        group: myGroup

Trident provisions a group snapshot

At this point, Trident receives a CSI request to create a group snapshot of the selected volumes.

This process creates several resources:

• A Kubernetes VolumeGroupSnapshot and VolumeGroupSnapshotContent custom resource (CR)
• A VolumeSnapshot and VolumeSnapshotContent CR for each volume in the group
• A TridentGroupSnapshot CR
• A TridentSnapshot CR for each individual snapshot in the group

Examples

In this concrete example, I've created a group snapshot for a group of two volumes. 

Let's walk through each resource, its purpose, and provide an example.

Kubernetes Custom Resources

Let's take a closer look at the following resources:

• A Kubernetes VolumeGroupSnapshot CR
• A Kubernetes VolumeGroupSnapshotContent CR
• Two Kubernetes VolumeSnapshot CRs
• Two Kubernetes VolumeSnapshotContent CRs

Volume Group Snapshot

This resource represents the request to create a group snapshot. 

Example

$ kubectl get volumegroupsnapshot -n trident -o yaml 
apiVersion: v1
items:
- apiVersion: groupsnapshot.storage.k8s.io/v1beta1
  kind: VolumeGroupSnapshot
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: | {"apiVersion":"groupsnapshot.storage.k8s.io/v1beta1","kind":"VolumeGroupSnapshot","metadata":{"annotations":{},"name":"vgs1","namespace":"trident"},"spec":{"source":{"selector":{"matchLabels":{"group":"myGroup"}}},"volumeGroupSnapshotClassName":"csi-group-snap-class"}}
    creationTimestamp: "2025-06-26T18:32:42Z"
    finalizers:
    - groupsnapshot.storage.kubernetes.io/volumegroupsnapshot-bound-protection
    generation: 1
    name: vgs1
    namespace: trident
    resourceVersion: "200373"
    uid: 411d2111-89ea-4129-a454-015d1fd8ae85
  spec:
    source:
      selector:
        matchLabels:
          group: myGroup
    volumeGroupSnapshotClassName: csi-group-snap-class
  status:
    boundVolumeGroupSnapshotContentName: groupsnapcontent-411d2111-89ea-4129-a454-015d1fd8ae85
    creationTime: "2025-06-26T18:01:21Z"
    readyToUse: true

Volume Group Snapshot Content

This resource represents the fulfillment of the VolumeGroupSnapshot request.

Example

$ kubectl get volumegroupsnapshotcontent -n trident -o yaml 
apiVersion: v1
items:
- apiVersion: groupsnapshot.storage.k8s.io/v1beta1
  kind: VolumeGroupSnapshotContent
  metadata:
    creationTimestamp: "2025-06-26T18:32:42Z"
    finalizers:
    - groupsnapshot.storage.kubernetes.io/volumegroupsnapshotcontent-bound-protection
    generation: 1
    name: groupsnapcontent-411d2111-89ea-4129-a454-015d1fd8ae85
    resourceVersion: "200347"
    uid: df01c3d7-8e91-4b0f-b992-eddc0a99e6ab
  spec:
    deletionPolicy: Delete
    driver: csi.trident.netapp.io
    source:
      volumeHandles:
      - pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500
      - pvc-cf598c63-5fc6-42af-83b0-f490180d23aa
    volumeGroupSnapshotClassName: csi-group-snap-class
    volumeGroupSnapshotRef:
      apiVersion: groupsnapshot.storage.k8s.io/v1beta1
      kind: VolumeGroupSnapshot
      name: vgs1
      namespace: trident
      resourceVersion: "200331"
      uid: 411d2111-89ea-4129-a454-015d1fd8ae85
  status:
    creationTime: "2025-06-26T18:01:21Z"
    readyToUse: true
    volumeGroupSnapshotHandle: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    volumeSnapshotHandlePairList:
    - snapshotHandle: pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
      volumeHandle: pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500
    - snapshotHandle: pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
      volumeHandle: pvc-cf598c63-5fc6-42af-83b0-f490180d23aa

Volume Snapshots

These resources represent the request for a volume snapshot. For group snapshots, these will have a new "ownerReferences" entry that points to their parent VolumeGroupSnapshot as the owner.

Read more about owner references.

Example

$ kubectl get volumesnapshot -n trident -o yaml 
apiVersion: v1
items:
- apiVersion: snapshot.storage.k8s.io/v1
  kind: VolumeSnapshot
  metadata:
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - snapshot.storage.kubernetes.io/volumesnapshot-in-group-protection
    - snapshot.storage.kubernetes.io/volumesnapshot-as-source-protection
    generation: 1
    name: snapshot-08f47b907f2f006f5d890a80afe11fbb977f63554498833f217435d95e435045
    namespace: trident
    ownerReferences:
    - apiVersion: groupsnapshot.storage.k8s.io/v1beta1
      kind: VolumeGroupSnapshot
      name: vgs1
      uid: 411d2111-89ea-4129-a454-015d1fd8ae85
    resourceVersion: "200378"
    uid: 2345f17a-5e8a-4ff6-a77d-47c2cc7b34d9
  spec:
    source:
      persistentVolumeClaimName: pvc2-2
  status:
    boundVolumeSnapshotContentName: snapcontent-08f47b907f2f006f5d890a80afe11fbb977f63554498833f217435d95e435045
    creationTime: "2025-06-26T18:01:21Z"
    readyToUse: true
    restoreSize: 100Mi
    volumeGroupSnapshotName: vgs1
- apiVersion: snapshot.storage.k8s.io/v1
  kind: VolumeSnapshot
  metadata:
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - snapshot.storage.kubernetes.io/volumesnapshot-in-group-protection
    - snapshot.storage.kubernetes.io/volumesnapshot-as-source-protection
    generation: 1
    name: snapshot-258720deb7c66ef2f4198286be15515d5908186da7d1888c08af3800e3bfed1e
    namespace: trident
    ownerReferences:
    - apiVersion: groupsnapshot.storage.k8s.io/v1beta1
      kind: VolumeGroupSnapshot
      name: vgs1
      uid: 411d2111-89ea-4129-a454-015d1fd8ae85
    resourceVersion: "200370"
    uid: 0637880a-6134-428d-a8fc-67214c726e99
  spec:
    source:
      persistentVolumeClaimName: pvc2
  status:
    boundVolumeSnapshotContentName: snapcontent-258720deb7c66ef2f4198286be15515d5908186da7d1888c08af3800e3bfed1e
    creationTime: "2025-06-26T18:01:21Z"
    readyToUse: true
    restoreSize: 100Mi
    volumeGroupSnapshotName: vgs1
kind: List
metadata:
  resourceVersion: ""

Volume Snapshot Contents

These resources represent the result of creating the requested VolumeSnapshot.

Example

$ kubectl get volumesnapshotcontent -n trident -o yaml 
apiVersion: v1
items:
- apiVersion: snapshot.storage.k8s.io/v1
  kind: VolumeSnapshotContent
  metadata:
    annotations:
      groupsnapshot.storage.k8s.io/volumeGroupSnapshotHandle: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - snapshot.storage.kubernetes.io/volumesnapshotcontent-bound-protection
    generation: 2
    name: snapcontent-08f47b907f2f006f5d890a80afe11fbb977f63554498833f217435d95e435045
    resourceVersion: "200376"
    uid: 8e161f10-40f9-478a-a2f1-04a2d70fa8a4
  spec:
    deletionPolicy: Delete
    driver: csi.trident.netapp.io
    source:
      volumeHandle: pvc-cf598c63-5fc6-42af-83b0-f490180d23aa
    sourceVolumeMode: Filesystem
    volumeSnapshotRef:
      kind: VolumeSnapshot
      name: snapshot-08f47b907f2f006f5d890a80afe11fbb977f63554498833f217435d95e435045
      namespace: trident
      uid: 2345f17a-5e8a-4ff6-a77d-47c2cc7b34d9
  status:
    creationTime: 1750960881000000000
    readyToUse: true
    restoreSize: 104857600
    snapshotHandle: pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    volumeGroupSnapshotHandle: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
- apiVersion: snapshot.storage.k8s.io/v1
  kind: VolumeSnapshotContent
  metadata:
    annotations:
      groupsnapshot.storage.k8s.io/volumeGroupSnapshotHandle: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - snapshot.storage.kubernetes.io/volumesnapshotcontent-bound-protection
    generation: 2
    name: snapcontent-258720deb7c66ef2f4198286be15515d5908186da7d1888c08af3800e3bfed1e
    resourceVersion: "200362"
    uid: 5631b489-1bdf-4d47-a38d-153a08b944cf
  spec:
    deletionPolicy: Delete
    driver: csi.trident.netapp.io
    source:
      volumeHandle: pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500
    sourceVolumeMode: Filesystem
    volumeSnapshotRef:
      kind: VolumeSnapshot
      name: snapshot-258720deb7c66ef2f4198286be15515d5908186da7d1888c08af3800e3bfed1e
      namespace: trident
      uid: 0637880a-6134-428d-a8fc-67214c726e99
  status:
    creationTime: 1750960881000000000
    readyToUse: true
    restoreSize: 104857600
    snapshotHandle: pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    volumeGroupSnapshotHandle: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
kind: List
metadata:
  resourceVersion: ""

Trident Custom Resources

Trident adds its own custom resources when creating a volume group snapshot. These Trident CRs are not meant to be manipulated by users directly but may be viewed via kubectl or tridentctl.

As part of a group snapshot, Trident creates the following CRs:

• A TridentGroupSnapshot CR
• A TridentSnapshot CR

Trident Group Snapshot

This stores useful metadata about the group snapshot for Trident. Creating a group snapshot in Kubernetes should result in a 1-1 relationship between the TridentGroupSnapshot and Kubernetes VolumeGroupSnapshotContent.

Example

$ kubectl get tridentgroupsnapshot -n trident -o yaml
apiVersion: v1
items:
- apiVersion: trident.netapp.io/v1
  dateCreated: "2025-06-26T18:01:21.000Z"
  kind: TridentGroupSnapshot
  metadata:
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - trident.netapp.io
    generation: 1
    name: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    namespace: trident
    resourceVersion: "200340"
    uid: e905c9b1-73c4-48b2-92e6-ecedaaadbd39
  snapshotIDs:
  - pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
  - pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
  spec:
    internalName: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    name: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    version: "1"
    volumeNames:
    - pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500
    - pvc-cf598c63-5fc6-42af-83b0-f490180d23aa
kind: List
metadata:
  resourceVersion: ""

Trident Snapshot

This stores useful metadata about the individual snapshot for Trident. Creating a group snapshot in Kubernetes should result in a 1-1 relationship between Trident Snapshots and Kubernetes Volume Snapshot Contents.

Example

$ kubectl get tridentsnapshot -n trident -o yaml
apiVersion: v1
items:
- apiVersion: trident.netapp.io/v1
  dateCreated: "2025-06-26T18:01:21.000Z"
  kind: TridentSnapshot
  metadata:
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - trident.netapp.io
    generation: 1
    name: pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500-snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    namespace: trident
    resourceVersion: "200342"
    uid: 6e4e197e-2f13-4705-98f8-64df0a0fc475
  size: 104857600
  spec:
    groupSnapshotName: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    importNotManaged: false
    internalName: snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    name: snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    volumeInternalName: websterj_pvc_373e0043_ca12_42ab_bcd9_4360f0ddc500
    volumeName: pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500
  state: online
- apiVersion: trident.netapp.io/v1
  dateCreated: "2025-06-26T18:01:21.000Z"
  kind: TridentSnapshot
  metadata:
    creationTimestamp: "2025-06-26T18:32:47Z"
    finalizers:
    - trident.netapp.io
    generation: 1
    name: pvc-cf598c63-5fc6-42af-83b0-f490180d23aa-snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    namespace: trident
    resourceVersion: "200341"
    uid: 881bbe33-1553-485a-a0c7-f79142918bdd
  size: 104857600
  spec:
    groupSnapshotName: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    importNotManaged: false
    internalName: snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    name: snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
    volumeInternalName: websterj_pvc_cf598c63_5fc6_42af_83b0_f490180d23aa
    volumeName: pvc-cf598c63-5fc6-42af-83b0-f490180d23aa
  state: online
kind: List
metadata:
  resourceVersion: ""

Interacting with group snapshots via tridentctl

Trident's CLI, tridentctl, may be used to view group snapshots via the new "groupsnapshot" subcommand.

Example

$ tridentctl get groupsnapshot -h -n trident  
Get one or more group snapshots from Trident

Usage:
  tridentctl get groupsnapshot [<group snapshot name>...] [flags]

Aliases:
  groupsnapshot, gs, gsnap, groupsnapshots

Flags:
  -h, --help                help for groupsnapshot
      --max-snapshots int   Set the maximum number of snapshots (inclusive) to display when displaying grouped snapshots.
                            Setting this to 0 will show all snapshots in the group. (default 3)

Global Flags:
  -d, --debug               Set the log level to debug
  -k, --kubeconfig string   Kubernetes config path
      --log-level string    Log level (trace, debug, warn, info, error, fatal (default "info")
  -n, --namespace string    Namespace of Trident deployment
  -o, --output string       Output format. One of json|yaml|name|wide|ps (default)
  -s, --server string       Address/port of Trident REST interface (127.0.0.1 or [::1] only)

You may also specify an output format: "-o json|yaml|wide":

$ tridentctl get groupsnapshot -n trident  
+----------------------------------------------------+
|                        NAME                        |
+----------------------------------------------------+
| groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |
+----------------------------------------------------+

$ tridentctl get groupsnapshot -n trident -o wide
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+
|                        NAME                        |         CREATED          |                                       SNAPSHOTS                                        | SNAPSHOT COUNT |
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+
| groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85 | 2025-06-26T18:01:21.000Z | pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |              2 |
|                                                    |                          | pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |                |
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+

$ tridentctl get groupsnapshot -n trident -o json
{
  "items": [
    {
      "version": "1",
      "name": "groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85",
      "internalName": "groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85",
      "volumeNames": [
        "pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500",
        "pvc-cf598c63-5fc6-42af-83b0-f490180d23aa"
      ],
      "snapshotIDs": [
        "pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85",
        "pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85"
      ],
      "dateCreated": "2025-06-26T18:01:21.000Z"
    }
  ]
}

$ tridentctl get groupsnapshot -n trident -o yaml
items:
- dateCreated: "2025-06-26T18:01:21.000Z"
  internalName: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
  name: groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85
  snapshotIDs:
  - pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
  - pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85
  version: "1"
  volumeNames:
  - pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500
  - pvc-cf598c63-5fc6-42af-83b0-f490180d23aa

The wide format option will display 3 additional columns:

• CREATED
  • The creation timestamp.
• SNAPSHOTS
  • The snapshot handle of each constituent snapshot.
• SNAPSHOT COUNT
  • The snapshot count (# of constituent snapshots).

Because there may be a large number of snapshots in a single group snapshot, the number of snapshot handles is truncated to 3 but will display more should you supply the --max-snapshots flag. Specifying "0" will display all snapshots in the group.

$ tridentctl get groupsnapshot -o wide -n trident --max-snapshots=0
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+
|                        NAME                        |         CREATED          |                                       SNAPSHOTS                                        | SNAPSHOT COUNT |
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+
| groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85 | 2025-06-26T18:01:21.000Z | pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |              2 |
|                                                    |                          | pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |                |
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+

# If you specify a number less than the total count, but greater than 0, the list of constituent snapshot handles is truncated. 
$ tridentctl get groupsnapshot -o wide -n trident --max-snapshots=1
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+
|                        NAME                        |         CREATED          |                                       SNAPSHOTS                                        | SNAPSHOT COUNT |
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+
| groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85 | 2025-06-26T18:01:21.000Z | pvc-cf598c63-5fc6-42af-83b0-f490180d23aa/snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |              2 |
|                                                    |                          | ... (+1 more)                                                                          |                |
+----------------------------------------------------+--------------------------+----------------------------------------------------------------------------------------+----------------+

Additionally, Trident Snapshots taken as a group will have an extra field ("GroupSnapshot") identifying its Trident Group Snapshot parent:

$ tridentctl get snapshot -o wide -n trident
+-----------------------------------------------+------------------------------------------+--------------------------+---------+-------+---------+----------------------------------------------------+
|                     NAME                      |                  VOLUME                  |         CREATED          |  SIZE   | STATE | MANAGED |                   GROUPSNAPSHOT                    |
+-----------------------------------------------+------------------------------------------+--------------------------+---------+-------+---------+----------------------------------------------------+
| snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 | pvc-373e0043-ca12-42ab-bcd9-4360f0ddc500 | 2025-06-26T18:01:21.000Z | 100 MiB |       | true    | groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |
| snapshot-411d2111-89ea-4129-a454-015d1fd8ae85 | pvc-cf598c63-5fc6-42af-83b0-f490180d23aa | 2025-06-26T18:01:21.000Z | 100 MiB |       | true    | groupsnapshot-411d2111-89ea-4129-a454-015d1fd8ae85 |
+-----------------------------------------------+------------------------------------------+--------------------------+---------+-------+---------+----------------------------------------------------+

Notes & Considerations

• Constituent snapshots cannot be individually deleted via tridentctl while their parent TridentGroupSnapshotCR exists.
• Deleting a TridentGroupSnapshot with tridentctl is not recommended, as it may cause inconsistencies between Kubernetes and Trident.
• Always create and delete group snapshots by managing the Kubernetes VolumeGroupSnapshot resource.
• Deleting a VolumeGroupSnapshot also deletes all constituent snapshots, the TridentGroupSnapshot, and related TridentSnapshot resources.
• Constituent snapshots in a group may be consumed in the same ways standard Kubernetes volume snapshots are.
  • Learn more about working with snapshots in Trident.
• Constituent snapshots may also be imported to a different Kubernetes cluster independently of their group.
  • It is important for administrators to carefully consider how these constituents will be managed in the destination cluster. Consider using Trident's "notManaged" annotation or the "--no-manage" flag when importing the parent volume of a constituent snapshot to ensure constituent snapshots are not erroneously deleted. 
  • Learn more about importing volumes with Trident.
  • Learn more about importing snapshots with Trident.

The Road Ahead

In future releases, the Trident team plans to broaden support for volume group snapshots to the ONTAP-SAN-Economy, ONTAP-NAS, and ONTAP-SAN (NVMe) drivers. Try out our new volume group snapshot feature with ONTAP-SAN volumes and let us know what you think. 

Thanks for reading! 

References

• Working with snapshots in Trident
• Importing volumes with Trident
• Importing snapshots in Trident
• Creating volume group snapshots
• Kubernetes Volume Group Snapshot blog